1995 150hp evinrude fast idle after running for long period

1995 150hp Evinrude, Model# e150eleom, Serial#G03805931. I have had this problem for the last two seasons,continue to trouble shoot, but no one can find the problem. Starts fine, idles fine, operates perfect at full throttle for hour long trips, but after running for a while and when idling and or shut off and restart after a short period, the engine goes to fast idle aprox. 2500 rpm.I put it in gear to go and as i try to throttle up it dies, keep trying and it finally takes off and runs perfect. The following has been done according to several different mechanics to try to resolve the problem. replaced power pack, replaced rectifier, new priming bulb, new vapor seperator pump, new float,needle and seat, new water pump, new thermostats, new primer valve, new plugs, which always look good. cant find any fuel or air leaks. What should I try next? This problem never occurs when the engine is cold, always seems to happen after running hard for a long period or at idle speed for long periods. If I leave motor off for an hour or longer this problem dosent happen.

Re: 1995 150hp evinrude fast idle after running for long period

Sounds like the only thing those wrenches missed changing was the paint.<br />I sure would avoid putting it in gear when it's idling that fast. You're gonna be replacing the clutch dogs long before thier time.<br />Have you removed the cowl and looked at the carburetors, throttle linkage and position of the timer base when it's idling fast? Make sure the butterflies are closed and the timing base is in the full retard position. If the butterflies are closed and the timer base is retarded, put a timing light on it and see where the spark advance is. That 2500rpm idle is the idle range of the S.L.O.W mode idle.<br /><br />c/6<br /><br />Hooty